How to easily minimize waste using a potato smasher

Tough question - there are a lot of non-scientific ways to measure small/medium/large potatoes and nobody seems to agree on exactly what weight each is. However, there are a few ways I identify large vs medium at home.

In my experience, a large potato is about the size you would get in a restaurant (I know, not very specific). That is, when I cook at home, the potatoes I purchase tend to be medium - round (not oval) and about the size of a tennis ball or baseball. When I'm at a restaurant their potatoes are noticeably larger, and generally more oval shaped it seems (closer to a sweet potato in shape and size), which makes them great for stuffing like for a loaded baked potato. Luckily most of the recipes I have at home that involve potatoes don't require precise measurement, so I just stick with my eyeball measurements and don't even bother weighing them.

I found a source online that says this:

According to Shape magazine, eatbetteramerica.com and prevention, a medium potato is the size of a computer mouse, so somewhat bigger than that.

And I think I can get behind that answer. I'd say your average computer mouse (like, one you would get with a new PC, not a fancy third-party mouse) is about the size of an average medium potato. Another way to eyeball: I'm a 30 year old male with hands that are neither very large or very small. The medium potatoes in this bag are about the size of a loose fist for me. So a large potato would be bigger than either of those things.

As for measurements, I have a bag of medium potatoes and it says they're 5.3 oz (150g) a piece. I weighed one and it was closer to 6.5oz (185g). Based on that I'd say a large potato would be anything over 8oz (225g), pushing as high as 12oz (340g).

I found a way to search online for this info: calories. By searching for "large potato calories" I was able to find pages with weights and measures:

• 3 to 4 1/4 inches in diameter
• 300 grams (about 10.5oz)

So, in short, it seems like I would consider these good numbers:

• Medium potato: 2 to 3" in diameter, 5-8oz (140-225g)
• Large potato: 3 to 4.25" in diameter, 8-12oz (225-340g)

Below is a picture of the medium potato from my bag, compared to some common household/kitchen items. The gift card is the size of a normal credit card, and the knife is a common steak knife from my utensil drawer. Apparently a medium potato is almost exactly the size of a 1 cup measure!

First, potato is not the same as potato. Conventionally, potato salad is always made with waxy potatoes, because mealy potatoes' outer layers disintegrate when tossed with the sauce, much like making risotto. They are also less creamy in texture. But there is also the school of using mealy potatoes, because they absorb more seasoning, and also because some people like the soft texture. If you decide to go with mealy, use an acid in the cooking water (depending on your seasoning, choose vinegar, citric acid, or the neutral tasting cream of tartar). This will firm the potatoes. It isn't necessary for waxy potatoes.

Second, the cooking time depends strongly on size. You must cut them very evenly. Else you will have both undercooked and overcooked potatoes in the pot at any given moment (up to the time when you only have overcooked ones). Smaller pieces are easier to work with.

Third, you want to heat them as gently as possible. Start them in cold water, and cook them at a simmer, not at a boil.

There is no way to predict when the potatoes will be ready. Even if you cut them to the same size every time, the sort and the age of the potatoes will result in varying cooking times. When the time is near, you must look after them and try them constantly. Take out a piece, cut it in half, cool it in cold water, and chomp on the exact center. If it isn't crunchy, stop the cooking immediately and remove the water. The time window in which they are just right is quite short. Season them while they are hot, they will then absorb the sauce instead of just swimming in it the way cold potatoes do.